Multi-channel stereophonic sound reproducing system for electronic musical instruments

ABSTRACT

The multi-channel stereophonic sound reproducing system includes tone generators for generating tone signals each having a predetermined pitch and keyers each arranged to derive from the tone generators a tone signal having a pitch corresponding to the depressed one of a plurality of keys juxtaposed in the order of musical notes. Each of the tone signals derived through the keyers is applied to the preselected one of a plurality of tone coloring filters having frequency characteristics different from each other. Output signals from the tone coloring filters are supplied via individual resistors to a plurality of points in the longitudinal direction of an elongated resistor body to form a composite signal. The composite signal is separated into a plurality of components at other points each arranged between the adjacent ones of the first-mentioned points. All the signal components are supplied via the corresponding sections each including a volume controlled and an amplifier to a plurality of loudspeakers disposed in a spacious hall or room at a substantially equal interval to reproduce therefrom desired stereophonic musical sounds.

United States Patent 1191 Hirano June 18, 1974 [54] MULTI-CHANNEL STEREOPHONIC SOUND 3,619,469 11/1971 Adachi 84/1.24X REPRODUCING SYSTEM FOR 3,626,077 12/1971 Munch et a1 84/ 1.24 3,707,594 12/1972 Ichikawa 84/l.24 X ELECTRONIC MUSICAL INSTRUNIENTS 3,717,715 2/1973 Jordy 84/l.27 X [75] Inventor: Katsuhiko Hiram), Hamakita, Japan 3,748,598 7/ I973 Munch et a1 84/l.24 X [73] Asslgnee: g g fgg ig Primary Examiner-Richard B. Wilkinson p Assistant ExaminerAtanley J. Witkowski [22] Filed; July 6, 1972 Attorney, Agent, or Firm-Flynn & Frishauf [21] Appl. No.: 269,379 [57] ABSTRACT [30] Foreign Application Priority Data The multi-channel stereophonic sound reproducing J i 8 1971 J 46 59822 system includes tone generators for generating tone 1971 Japan 46'6O960 signals each having a predetermined pitch and keyers uy apan each arranged to derive from the tone generators a tone signal having a pitch corresponding to the dei 84/1'24 84/DIG' Pressed one of a plurality of keys juxtaposed in the [58] Fieid l 11 1 19 order of musical notes. Each of the tone signals de. 84 22 -l 2 7 -1 0; rived through the keyers is applied to the preselected l 179/! A 1 G 100 one of a plurality of tone coloring filters having frequency characteristics different from each other. [5 References Cited Output signalstrom the tone coloring filters are UNITED STATES PATENTS supplied via individual resistors to a plurality of points in the longitudinal direction of an elongated resistor g r body to form a composite signal. The composite signal 22986l8 10/1942 SMDIC 27 is separated into a plurality of components at other 2:500:820 3/1950 naneitumifi 1111. 84/1 .19 Points h arrangcid betweemh? adlacel'tonesofthe 2,538,869 H195, 179/1003 T first-mentioned points. All the signal components are 2,822,429 2/1958 Watson 84/D1G. 27 pp via the Corresponding Sections each including 2,931,862 4/1960 Vermeulen et a1, 84/D1G. 27 a volume controlled and an amplifier to a plurality of 3,147,333 9/1964 Wayne 84/ 1.24 loudspeakers disposed in a spacious hall or room at 21 3,215,767 ll/l965 Martin 84/1.24 substantially equal interval to reproduce therefrom desired stereophonic musical sounds. es 1e r 3,610,804 10/1971 Matsuura 84/1.24 x 14 Chums, 8 Drawlng Figures OUTPUT Cl-lAhNEL 11 1 R I; 2 2 1 1' i Milli-Hill 1 f i I H 3 11, 1 I J i TONE I J i GENERATORS 1 1 3 PUT C1-1AN\L 2 TPUT CHANNEL 1 OUTPUT CHANNEL PATENTEDJUN 1 4w 3Q818l 1 1 5 SHEET 2 OF 8 FIG. 2

g? 23 v 23? Q s V w HALL OR ROOM 18mins PATENTEDM 1a 1924 SHEET 3 0F 8 umb J om EMP m 02710400 mZOP v nIN w om.

WEOCEwZmO mzok w 02 BACKGROUND OF THE INVENTION However, electronic musical instruments constructed as described above have the drawback that they can not realize a stereophonic sound effect substantially true to that of an orchestral performance, although they can attain a pseudostereophonic sound effect by expanding an audible region defined by a sonic energy emanated from all the loudspeakers.

' As the result of noticeable development of the technique of reproducing stereophonic sounds there has recently grown a strong demand for the realization of an electronic musical instrument capable of attaining an excellent stereophonic sound effect.

'It is therefore the object of this invention to provide a multi-channelgstereophonic sound reproducing system for an electronic musical instrument capable of attaining a stereophonic sound effect substantially true to that of an orchestral performance. I

SUMMARY OF THE INVENTION According to the multi-channel stereophonic sound reproducing system of this invention, tone signals which have predetermined pitches and are derived from tone generators through keyers actuated by the selective depression of a plurality of manual and/or pedal keys of an electronic musical instrument arranged in the order of musical notes are coupled to a resistor network through respective tone coloring filters each having different frequency characteristics, thereby to form a composite signal. The composite signal' is separated into a plurality of components from dif ferent points on the resistor network. Each of the signal components thus obtained is supplied through the corresponding section including a volume controller and an amplifier to the predetermined one of a plurality of loudspeakers.

Since they have frequency characteristics differing successively one from the other, musical sounds reproduced from a combination of such loudspeakers can cause listeners present in a listening area in which the instrument is disposed to enjoy a stereophonic sound effect substantially true to that of an orchestral performance.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 2 is a schematic plan view of a combination of 'a plurality of loudspeakers which are disposed in a spacious hall or room and are connected to the individual output channels of FIG. 1;

FIGS. 3 to 5 show schematic block circuit diagrams of a stereophonic sound reproducing system suitable for practical use which is arranged in accordance with the embodiment of FIG. 1',

FIG. 6 indicates a similar block circuit diagram of a stereophonic sound reproducing system prepared by replacing the elongated resistor body of FIG. 1 with a series combination of a plurality of resistors;

FIG. 7 is a schematic block circuit diagram of a stereophonic sound reproducing system according to another embodiment of this invention; and

v FIG. 8 is a similar block circuit diagram showing one modification of a stereophonic sound reproducing system used when it is in a multi-channel form in accordance with the embodiment of FIG. 7.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A stereophonic sound reproducing system according. to the preferred embodiments of this invention will now arranged in the order of musical notes; tone generators 13 which generate tone signals each of a predetermined pitch or frequency corresponding to the preset one of musical notes allotted to the respective keys 11, to 11, on the keyboard 12; keyers 14 eacharranged to be actuated upon the selective depression of the keys 11, to 11,, on the keyboard 12 so as to produce therethrough .a tone signal of a pitch corresponding to the depressed key; and a plurality of tone coloring filters 15,, 15 15 15,, 15,, of the undermentioned construction each receiving the predetermined ones of the tone signals obtained through the keyers 14.'

The respective tone coloring filters 15, to 15,, are comprised of, as it is well known to those skilled in the art, a differentiator, an integrator, a series resonance or a parallel resonance type circuit or combinations thereof and have frequency characteristics different from each other. For example, the first tone coloring filter 15, is so designed to form a musical tone having a color substantially true to that of a flute, and the remaining tone coloring filters 15 to 15,, are so designed as to give forth musical tones having colors practically resembling those of other natural musical instruments such as a diapason, a brass instrument, a clarinet, an oboe and a string instrument.

Output signals obtained at the coloring filt'ers 15, to 15,, are transmitted to their respective resistors 16,, 16 16 16,, 16,, each having a proper value and then are supplied together to an elongated resistor body 17 of such a construction as will be described hereinafter. The elongated resistor body 17 has opposite ends respectively supplied with output signals from the first and last tone coloring filters l5, and 15,, and has a plurality of first taps 18 which are arranged in the longitudinal direction thereof at substantially equal intervals and are supplied respectively with separate output signals from the remaining tone coloring filters 15 to 15,,.,. The elongated resistor body 17 has also other taps 19 which are arranged between any adjacent two first-mentioned taps 18 and between the first tap l8 and the one end' of the elongated resistor body 17 as well as the last tap 18 and the other end thereof. Therefore, there are derived from the second-mentioned taps 19 of the elongated resistor body 17 signal components into which the composite signal has been split. The individual signal components thus obtained are supplied to the corresponding output channels 22 through the corresponding volume controllers 20 and amplifiers 21.

Each of the output channels 22 is connected to the preselected one of a plurality of loudspeakers 23 which are disposed in a spacioushall or room at substantially equal intervals, for example, asshown in FIG. 2.

In the stereophonic sound reproducing system so constructedasdesc'ribed above, there are reproduced from the respective loudspeakers 23 musical sounds each having such a tone color that output signal components from the tone coloring filters 15 to 15,, are mixed in a ratio defined by the position of the corresponding tap 19 relative to the elongated resistor body 17.

For example, musical sounds from the loudspeaker 23 of the first channel have a greater part occupied-by the mixture of output signal components from the first and second tone coloring filters 15, and 15 and have the remaining parts occupied by the output signal components from the remaining tone coloring filters 15 to 15 Similarly, the greater part of musical sounds from the second-channel loudspeaker 23 is occupied by the blend of output signal components from the second and third tone coloring filters 15 and 15;, and the remaining parts are occupied by output signal components from the remaining tone coloring filters.

As a result, the stereophonic sound reproducing system of this invention has the advantage that it can attain a stereophonic sound effect practically resembling that of an orchestral performance, since there are reproduced from the loudspeakers 23 musical-tones whose colors vary successively from the left to the right or vice versa and whose. volumes regularly differ from each other in response to the momentarily changing performance of the instrument.

FIG. 3 shows a practical construction of a stereophonic sound reproducing system according to the embodiment of FIG. 1. In this construction, the entire scale of musical notes (C -to C for example) of an electronic musical instrument are separated into a plurality of groups (five groups-of C to E F to A A to D D 5 to G and G# 6 to C in this case) and consequently keyers 140 are grouped for each of the musical note sections.

Thus, tone signals obtained from tone generators 13a through the different groups of keyers l4a upon the selective depression of keys on a keyboard 12a are devised to be supplied to corresponding tone coloring filters 15a l5a 15a 15:1 and l5a FIG. 4 is another practical constructionof a stereophonic sound reproducing system according to the embodiment of FIG. 1. In the construction, keyers 14b for an electronic musical instrument are grouped for each of a plurality of coupler registers (three 16 feet, 8 feet and 4 feet couplers in this case). Tone signals derived through the first keyer portion corresponding to the 16 feet coupler are supplied to a single tone coloring filter 1512 which is designed to form a color similar to that of, for example, a bourdon; those obtained through the second keyer portion corresponding to the 8 feet coupler are supplied in a predetermined relationship to three tone coloring filters 15b 15b and 15b, which are designed to present colors very similar to those of e.g., a flute, a trumpetand an oboe; andthose drawn out through the third-keyer portion corresponding to the 4 feet coupler are supplied in a prescribed relationship to two tone coloring filters 1517 and 1517 which are so devised as to form colors similar to those of, e.g., a flute and a string instrument.

FIG. 5 shows still another practical construction of a stereophonic sound reproducing system according to the embodiment of FIG. 1.

In this construction, three keyers 14c 140 and 140 are provided for an upper or great manual keyboard a lower or swell keyboard 12c and a pedal keyboard 12c respectively. Thus, tone signals derived through the keyers corresponding to the upper manual keyboard 12c,, are supplied in a predetermined relationship to three tone coloring filters 15c and l5c which are so designed as to form colors closely resembling those of, e.g., a diapason, aflute and a clarinet; those drawn out through the keyers 140 corresponding to the lower manual keyboard 120 are supplied in a predetermined relationship to three tone coloring filters 150 150 and 15c which are so made as to attain colors similar to those of, for example, a melodia, a trumpet and an oboe; and those obtained through the keyers 14c corresponding to the pedal keyboard 12c are supplied to a single tone coloring filter 150-, which is'devised to produce a color similar to that of, e.g., a sub bass.

With the stereophonic soundreproducing systems constructed as shown in FIGS. 3 to 5, it will be apparent to those skilled in'the art how to attain substantially the same effect as the embodiment of FIG. 1.

. FIG. 6 shows a schematic block circuit diagram of one modification prepared by replacing'the elongated resistor body 17 with a series combination 171 of a plurality of resistors (or variable resistors) R R R R,, Rn each having a pair of common connections 181 to the adjacent ones of the-resistors R to R which are supplied with individual output signals from prescribed tone coloring filters 15:1 15d 15 output signals from the first and last tone coloring filters 15d and 15d being supplied to the opposite ends of the series resistor combination 171, and having a top (ora movable contact) 191 which is connected toa corresponding output channel 22d via volume controller 20d and an amplifier 21d.

FIG. 7 is a block circuit diagram of a stereophonic sound reproducing system according to another embodiment of this invention. In this embodiment, there is so arranged as to replace the elongated resistor body 17 having two sets of taps l8 and 19 in the embodiment of FIG. 1 with a plurality of resistor networks 31, 32, 3n comprising variable resistors VR,, VR VR, which have a movable contact connected to the preselected one of tone coloring filters 15s,, 15e 15, and respective two resistors R -R R ,-R R ,-R,, provided if required, which have one end connected to the corresponding one of the variable resistors VR to VR,, and have the other end connected in common to the corresponding one of two output channels 222 via individual amplifiers 21 and volume controllers 20. In this construction, there are respectively supplied with musical sounds each consisting of a plurality of mixed components which have split tone signals from the tone coloring filters l5e to :2 in a ratio determined by the respective positions of movable contacts on the variable resistors VR to VR included in the resistor networks 31 to 3n to the two output channels 22e.

In order to realize a further multi-channel form according to the embodiment of FIG. 7, tone coloring filters used in an electronic musical instrument have only to be so constructed that they can be separated into a plurality of groups, for example, as shown in FIG. 8 (two groups in FIG. 8).

In practice, as illustrated in FIGS. 3 to 5, the tone coloring filters are so separated into groups so that the filters of a group may be so devised as to correspond to the preselected one of all the musical notes, all the couplers or all the keyboards for the instrument.

It will be apparent to those skilled in the art how to attain substantially the same effect as those of FIGS. 1 and 3 to 6 in the stereophonic sound reproducing system constructed as described above.

In FIG. 1 and FIGS. 3 to 8, the loudspeakers may be installed in an electronic musical instrument as well as in a spacious hall or room as shown in FIG. 2.

The parts of FIGS. 3 to 8 corresponding to those of FIGS. 1 and 2 are respectively denoted by the corresponding numerals and description thereof is omitted.

What is claimed is:

I. ha keyboard electronic musical instrument hav ing tone generators for generating a plurality of tone signals each having a predetermined pitch, keyers coupling out from the tone generators a tone signal having a pitch corresponding to the depressed one of a plurality of keys arranged in the order of musical notes, and a plurality of tone coloring-filters each having different frequency characteristics and supplied with the preselected ones of the tone signals derived through the keyers;

a multi-channel stereophonic sound reproducing system comprising:

a resistor network including a plurality of variable resistance elements each of said tone coloring filters being coupled to a variable resistance element for adjustably combining collectively output signals from the respective tone coloring filters to form composite signals;

a signal separation means connected to said resistor network for separating a composite signal formed by the resistor network into a plurality of components, said separation means including a plurality of sections each including an amplifier; and

a plurality of loudspeakers each connected to a respective one of said sections and receiving the preset one of the signal components obtained by the corresponding sections, whereby stereophonic musical sounds are reproduced from the combination of all the loudspeakers.

2. A multi-channel stereophonic sound reproducing system according to claim 1 wherein said tone coloring filters are arranged to receive signals corresponding to preset ones of all the musical notes of the instrument.

3. A multi-channel stereophonic sound reproducing system according to claim 1 including a plurality of couplers connected to said keyers and wherein respective tone coloring filters are coupled to one of said couplers.

4. A multi-channel stereophonic sound reproducing system according to claim 1 wherein said keys are arranged in a plurality of keyboards, and said tone coloring filters are respectively separately coupled to a preset one of the keyboards of the instrument.

5. A multi-channel stereophonic sound reproducing system according to claim 1 wherein said resistor network comprises at least one elongated resistor body which has opposite ends connected with the first and last ones of a group of said tone coloring filters and has a plurality of adjustable taps spaced in the longitudinal direction of the elongated resistor body and connected with the remaining tone coloring filters of said group.

6. A multi-channel stereophonic sound reproducing system according to claim 1 wherein said resistor network comprises a series combination of a plurality of variable resistance elements, said series combination having opposite free ends connected with the first and last ones of said tone coloring filters, a plurality of common connections to the respective adjacent ones of the resistance elements connected with the remaining tone coloring filters, and a plurality of contacts arranged on the individual resistance elements, said contacts being coupled to said signal separation means.

7. A multi-channel stereophonic sound reproducing system according to claim 1 wherein said resistor network comprises a plurality of variable resistors having movable contacts each connected with the preselected one of said tone coloring filters and having opposite end terminals connected to respective ones of two loudspeakers via its respective section of said signal separation means.

8. A multi-channel stereophonic sound reproducing system according to claim 7 wherein said resistor network includes at least two groups of said variable resistors, each group being coupled to respective tone coloring filters for combining output signals therefrom, thereby attaining a further multi-channel form.

9. A multi-channel stereophonic sound reproducing system according to claim 7 further including a pair of resistors connected to both ends of each of said varispaced in the longitudinal direction of the elongated resistor body and connected with the remaining tone coloring filters, said elongated resistor body further comprising another group of adjustable taps each arranged between the adjacent ones of said firstmentioned plurality of taps, said another group of taps being coupled to said signal separation means.

12. A multi-channel stereophonic sound reproducing system according to claim 5 comprising another group of taps each of which are arranged between the adjacent ones of said first-mentioned plurality of taps, said 7 another group of taps being adjustable and being coupled to said signal separation means.

13. A multi-channel stereophonic sound reproducing system according to claim 6 wherein said plurality of contacts are adjustably arranged on the individual resistance elements.

14. A rnulti-channel stereophonic sound reproducing system according to claim 1 wherein said resistor net- 

1. In a keyboard electronic musical instrument having tone generators for generating a plurality of tone signals each having a predetermined pitch, keyers coupling out from the tone generators a tone signal having a pitch corresponding to the depressed one of a plurality of keys arranged in the order of musical notes, and a plurality of tone coloring filters each having different frequency characteristics and supplied with the preselected ones of the tone signals derived through the keyers; a multi-channel stereophonic sound reproducing system comprising: a resistor network including a plurality of variable resistance elements each of said tone coloring filters being coupled to a variable resistance element for adjustably combining collectively output signals from the respective tone coloring filters to form composite signals; a signal separation means connected to said resistor network for separating a composite signal formed by the resistor network into a plurality of components, said separation means including a plurality of sections each including an amplifier; and a plurality of loudspeakers each connected to a respective one of said sections and receiving the preset one of the signal components obtained by the corresponding sections, whereby stereophonic musical sounds are reproduced from the combination of all the loudspeakers.
 2. A multi-channel stereophonic sound reproducing system according to claim 1 wherein said tone coloring filters are arranged to receive signals corresponding to preset ones of all the musical notes of the instrument.
 3. A multi-channel stereophonic sound reproducing system according to claim 1 including a plurality of couplers connected to said keyers and wherein respective tone coloring filters are coupled to one of said couplers.
 4. A multi-channel stereophonic sound reproducing system according to claim 1 wherein Said keys are arranged in a plurality of keyboards, and said tone coloring filters are respectively separately coupled to a preset one of the keyboards of the instrument.
 5. A multi-channel stereophonic sound reproducing system according to claim 1 wherein said resistor network comprises at least one elongated resistor body which has opposite ends connected with the first and last ones of a group of said tone coloring filters and has a plurality of adjustable taps spaced in the longitudinal direction of the elongated resistor body and connected with the remaining tone coloring filters of said group.
 6. A multi-channel stereophonic sound reproducing system according to claim 1 wherein said resistor network comprises a series combination of a plurality of variable resistance elements, said series combination having opposite free ends connected with the first and last ones of said tone coloring filters, a plurality of common connections to the respective adjacent ones of the resistance elements connected with the remaining tone coloring filters, and a plurality of contacts arranged on the individual resistance elements, said contacts being coupled to said signal separation means.
 7. A multi-channel stereophonic sound reproducing system according to claim 1 wherein said resistor network comprises a plurality of variable resistors having movable contacts each connected with the preselected one of said tone coloring filters and having opposite end terminals connected to respective ones of two loudspeakers via its respective section of said signal separation means.
 8. A multi-channel stereophonic sound reproducing system according to claim 7 wherein said resistor network includes at least two groups of said variable resistors, each group being coupled to respective tone coloring filters for combining output signals therefrom, thereby attaining a further multi-channel form.
 9. A multi-channel stereophonic sound reproducing system according to claim 7 further including a pair of resistors connected to both ends of each of said variable resistors.
 10. A multi-channel stereophonic sound reproducing system according to claim 1 wherein each of said sections of said signal separation means include a volume controller coupled to said amplifier for controlling the output of the respective loudspeaker.
 11. A multi-channel stereophonic sound reproducing system according to claim 1 wherein said resistor network comprises an elongated resistor body which has opposite ends connected with the first and last ones of said tone coloring filters and has a plurality of taps spaced in the longitudinal direction of the elongated resistor body and connected with the remaining tone coloring filters, said elongated resistor body further comprising another group of adjustable taps each arranged between the adjacent ones of said first-mentioned plurality of taps, said another group of taps being coupled to said signal separation means.
 12. A multi-channel stereophonic sound reproducing system according to claim 5 comprising another group of taps each of which are arranged between the adjacent ones of said first-mentioned plurality of taps, said another group of taps being adjustable and being coupled to said signal separation means.
 13. A multi-channel stereophonic sound reproducing system according to claim 6 wherein said plurality of contacts are adjustably arranged on the individual resistance elements.
 14. A multi-channel stereophonic sound reproducing system according to claim 1 wherein said resistor network includes a plurality of fixed resistance elements respectively coupled to the outputs of said tone coloring filters, said fixed and variable resistance elements being coupled together to combine said output signals from said tone coloring filters to form said composite signals. 